Three's (Not) A Crowd
by SandraG87
Summary: Prompt fill for kink meme '13. Prompt 1: Castle/Beckett/Other dude. Beckett wants both her ass and her cunt filled at the same time. Prompt 2: Beckett/Castle/Colin Hunt. Hunt's back in NYC for whatever reason and crosses path with CB again. - Translation by Anonymous. Thanks for that!
1. Chapter 1

Kate was in the middle of storing her groceries in the fridge, when her door bell rang. Shit, who could that be? With Castle having to work on his book, she was looking forward to a quiet evening with a hot bath and a glass of wine. Visitors were definitely not welcome right now.

Irritated, she flung her door open and came face to face with Detective Inspector Colin Hunt of the Scotland Yard.

"Surprise," he smiled, as he greeted her.

"Hey," she returned and her anger regarding the unannounced visitor quickly dissipated. "Since when are you in town?"

"This morning," Colin replied and wrapped his arms around Kate. "Some complicated case I'm liaising with Interpol. Don't ask. I came as quickly as I could get out of the meeting."

He pressed her close and let his lips travel across her face in kisses. Kate draped her arms around his neck and pulled him even tighter. Finally his mouth found hers and she opened her lips to grant his tongue access. They kissed passionately until they had to gasp for air.

"Hmm, missed you," Colin hummed into her ear. Kate laughed out loud. She could clearly feel how happy he was to see her, since it was hard to ignore his erection. And if the tingling between her legs were any indication, she was really happy to see him, too.

"Come inside," Kate said and dragged him into her apartment, realizing they were still standing on the threshold of her door.

While Kate closed the door, Colin took off his Jacket and shoes. He wanted to pull Kate in for another kiss, but she stopped him with her hand against his chest.

"There's been some developments since the last time," she answered the question he hadn't voiced out loud, "Castle and I are together, now."

"So?" He looked at her confused.

"I just thought you should know that," she explained and lowered her gaze with guilt.

"Kate," Colin said and lifted her chin with two fingers, so he could look into her eyes. "I've always known that you belong with Castle. There's never been any doubt about that, so it's okay with me. I like hooking up with you, when I'm in New York, but I also know that that's all we'll ever be." He gave her a calculating look. "The question simply is do you want me to leave and be out of your life forever?"

Kate pondered her decision carefully. She loved Castle more than anything, and she had very strong qualms about cheating on him, but she just couldn't miss out on one of her rare hook ups with Colin. There was something about the Brit that made him irresistible. Whether it was his accent or his well-toned body, Kate didn't know. What she did know was that she couldn't let go of him.

"Stay," she made her decision and the word had barely left her mouth when Colin crowded her into the next wall. He plunged his tongue into her mouth and squeezed his hand into her pants. His fingertips parted her wet lips and Kate moaned into his mouth.

God, yes, she wanted him.

Her hands slipped underneath his sweater and he interrupted their kiss only so long it took her to pull the garment over his head. Kate unbuttoned his pants blindly, dragging the zipper down, so she could bury her hands in his underwear. His hot and hard cock pressed into her palm.

They kept stimulating each other like that, and Kate was just about to suggest taking things into her bedroom, lest she came in her clothes, when something caught her attention out of the corner of her eye. She turned her head and saw him.

Castle.

He gazed at her stunned and Kate stared back at him in shock. Colin came to his senses first and pulled his hand out of Kate's pants.

"Hi Castle, how's it going?" He tried for nonchalance.

Speechless, Castle placed the wine and bag of Chinese onto the kitchen counter and turned to leave. Coming out of her shock, Kate sprinted after him and grabbed his arm.

"Rick, please, let me explain," she implored him.

Castle turned around slowly, but instead of the anger she expected all she could see was disappointment. She didn't know what was worse.

"I can't wait to hear your explanation for this," Castle shook off her hand and fell unto the couch. He prompted her with his eyes. Kate straightened out her attire and ran her fingers through her hair. She was stalling.

"Colin's here on business." Kate started.

"Oh!" Castle sneered, "Well then that explains everything."

"Rick, just please," she begged him again and Castle held up his hands as an apology. "Remember the case we worked with Colin?" He nodded. "I slept with Colin after we closed it."

"Still doesn't explain why I caught him with his hands down your pants now." Castle fretted.

'Yeah well, we've been seeing each other when he's in town ever since." Kate clarified.

"You've slept with him, while we've been together?" He asked her with disbelief.

"No, of course not!" Kate shot back. "The last time I saw him was half a year ago. We weren't even together then."

"Kate, clearly things aren't as black and white as you make them out to be," Castle noticed. "If I hadn't walked in on you, the two of you would be lying together in your bed, right?"

Kate looked to Colin for help, but he just shrugged his shoulder, sporting a grin.

"Okay, Castle, you're right." Kate rubbed her eyebrows and sighed, "And I'm sorry. It won't happen again."

"Ha!" Castle jumped off the couch. "I don't think so. I saw you. You were a goner. Do you want to leave me for that limey?" He yelled and threatened Colin with a finger.

"I better leave," Colin reasoned and pulled on his sweater.

"No!" Kate yelled back and both men looked at her surprised. "I mean, no, I don't want to leave you, I love you", she spoke to Castle with a quiet voice. "Only you," she added with more confidence.

After a moment of silence Kate walked over to Rick and took his hand, then reached with her other hand for Colin, who took it hesitantly.

She looked between both men and sighed deeply. "Why can't I have both of you?" She asked quietly.

"You're not being serious, Kate, are you?" Castle shook his head in disbelief and freed himself to pace the floor.

But Kate simply nodded, "I am."

"I'm game," Colin interjected, earning a glare from both Kate and Castle.

"Could you give me a minute alone with Castle?" It was really more of an order than a request. Colin nodded and moseyed into the kitchen, where he stuck his head into her fridge in search of a drink.

Kate followed him with her eyes and once she was sure he was out of earshot, she turned back to Castle. She walked over to him, clasped his hands in hers and gave them a squeeze.

"Rick, I love you," she whispered lovingly, "and I wanted to spend the rest of my life together with you."

"But?" Castle studied her eyes carefully.

"There's something about Colin I can't resist. I can't even tell you what it is about him, but I want him." Kate sighed, "I'm so sorry."

"And to keep me from pouting you want to include me in your little sex games?" He asked her skeptically.

Kate laughed, "Do you remember our ski trip?" Caslte nodded. "That night we spent together with the ski instructor?" Now Castle was grinning. "That was one of the hottest nights I've ever experienced. That was your fantasy having two women together. And we lived it out. I've got threesome fantasies, too, only it's with two men and one of them should definitely be you." She looked at him questioningly. "Now it's my turn. Do you think that's something you could live with?"

Castle stepped into Kate's personal space and rested his hands on her hips thoughtfully. She could see the cogwheels in his brain turning. After what felt like eternity a grin spread over his face.

"The more I think about it, the more it turns me on just thinking about watching another man satisfy you." Castle wrapped his arm around her waist and pulled her flush against his body. "And Colin's a pretty nice bloke after all."

Now it was Kate who was surprised at how quickly Castle took to her idea. "Are you sure?"

"No," he replied on a smile, "but I love you. And if that's what you want, let's do it." He pointed to Colin who was leaning against the kitchen counter, nursing a bottle of beer. "But first I want to talk to him. Alone."


	2. Chapter 2

A/N: Yes, it's OOC. But it's a Kink Meme. So what?

* * *

Kate bit her thumb nervously, while she sat waiting on the bed in her room. What could Castle possibly have to say to Colin that could take them so long? She considered it positive that there had been no yelling and cussing so far. She was just about to return to the living room to put an end to it, when the door to her bedroom finally opened and revealed both men. Castle entered first.

"Okay, we're ready," Coline said, closing the door before stepping up next to Castle' "How shall we do it?"

Kate gave a laugh of relief, after all she had been slightly worried that Castle would end up tearing off Colin's head.

"How about you two strip for me. Then you can undress me?" Kate suggested after a very short deliberation. The men exchanged a glance, then nodded and quickly took off their clothes. Kate had actually expected them to make a show out of it, but apparently that would take things a bit too far. She could feel they were just as nervous as she was.

Colin was naked first, which had less to do with Castle's lack of zeal and more to do with the fact that her boyfriend was still wearing all his clothes - shoes and a shirt with way too many buttons included.

When they finally stood butt naked in front of her, Kate let her eyes wander across their buddies unabashedly. Both were very fine, well-endowed specimen. Giddy with anticipation, Kate licked her lips. She was already wet, wetter than she'd been in a long time, even though neither men had even touched her.

Kate rose from the bed and stood between Castle and Colin, where she casually stroked their semi-erect cocks - as if by accident.

Colin clasped her hips and turned her toward him. He kneeled down in front of her and began to take off her pants. Castle stepped behind Kate and reached around her to unbutton her blouse, while his lips nuzzled her neck.

Castle pushed down her open blouse, letting it glide to the floor carelessly, and immediately devoted himself to her bra, which ended up next to the blouse on the floor in a flash. Meanwhile Colin had pulled Kate's pants along with her slip down to her ankles. He leaned over, kissing her pubic mound, and let his tongue wander. Kate tried to spread her legs but the pants foiled her attempts.

"Take them off," she panted and Colin followed her orders. Castle held her, while Colin lifted her legs, one by one, getting rid of her shoes, socks and finally her pants.

Kate leaned into Castle's chest and draped one leg over Colin's shoulder. He brushed her inner thigh with his lips and moved his mouth slowly where Kate craved it the most.  
Castle had his arms wrapped around his girlfriend to keep her upright. His hands caressed her breasts, alternating between massaging them and twisting her nipples between his fingers.

When Colin's tongue finally met her labia, Kate moaned out loud and let her head drop onto Castle's shoulder. She turned her head so she could kiss him. This was better than any fantasy with Castle's tongue in her mouth and Colin's tongue on her clit at the same time.

Castle rubbed his erection against Kate's back, while his hands ghosted over her torso. Colin kept working on her, sucking and licking as if his life depended on it. The minute he pushed two fingers into her, Kate was gone. Her orgasm hit her hard and fast, as she twisted and shuddered in Castle's arms.

Colin withdrew and Castle lifted Kate into his arms so he could carry her to the bed. Both men took in the woman hungrily, who lay in front of them the picture of seduction, still shivering from the aftermath of her strong climax.

After her heartbeat returned to somewhat normal, Kate opened her eyes and spotted both man admiring the view. She smiled and nodded at them encouragingly. She needed more.

Colin sent Castle a glance, who nodded. He wanted to see how the other man takes his girlfriend. Colin didn't waste any time and knelt between Kate's spread legs. He angled her hips up a little and penetrated her with a swift and smooth stroke.

All three of them moaned and Kate looked at Castle, who was standing next to the bed watching them fuck. She could see the war of emotions on his face. On the one hand he was hurt to see her with another man, but on the other hand, it turned him on like crazy to watch Colin's cock disappear into her tight pussy and reemerge coated in her juices in a steady rhythm.

Kate found it even more arousing to watch her boyfriend fondle himself as he watched her being taken by another man. She was wetter than ever before.

Castle noticed her watching him and grinned. "You like being watched," he observed and Kate nodded with a moan. "Good, I like watching you, too."

"Let me touch you," Kate begged in a hoarse voice and Castle knelt down next to her on the mattress. She took his hard shaft into her hand, while Colin pumped into her ever faster and harder.

Castle closed his eyes and gave into the exciting feeling of being masturbated by his girlfriend. She knew him too well, knew exactly, how fast and firm she had to move her hand. She knew all his sensitive spots and caressed them. He was so fucking close.

"Kate, I'm coming," he warned her and groaned, seconds before he squirted his sperm across his girlfriend's breasts.

His hot cum on her skin triggered another orgasm for Kate and she came again moaning out loud. Her inner muscles clenched spastically, as the waves of her release crushed over her.

Colin thrust into her a few more times before he let go with a grunt, flooding her womb with his cum. Completely sated, he fell into bed with Kate and Castle.

They relaxed for a few minutes until Colin rose. "That was so fucking hot," he noted satisfied, "but I should be going now."

"No, Colin, stay." Kate blushed a little, realizing how eager she must come across. "I'm not finished with you two." There was something else, she'd been dreaming of for a long time and perhaps today was right to make her dream come true.


	3. Chapter 3

Kate went into the bathroom first, then it was Castle's turn. Finally Colin disappeared in the en-suite, and as soon as the door fell into the lock behind him, Kate turned to Castle.

"Rick, if you want to stop, all you have to do is say the word." She prompted him. "I don't want to force you into anything."

Castle gave a laugh, "A little bit late for that now, is it? But thanks for the offer." Kate rolled her eyes. Castle crossed the floor to take her in his arms and looked at her seriously. "Kate, I love you and this is by far the hottest experience of my life. The hell I want to stop now."

"I love you, too," she replied and they kissed passionately.

They didn't interrupt their kiss, when Colin returned form the bath. It didn't really bother the Brit anyway, this way he could observe them in quiet. Colin liked being with attractive, sexually open-minded people, which included both Kate and Castle for him. He let his gaze wander over Castle's broad back, his muscled arms, and his firm butt. Just the look of the couple kissing passionately in front of him was enough to harden his cock.

"Nice of you two starting without me," Colin smirked. "Now what's next?"

Castle and Kate tore themselves away from their kiss and looked at Colin who stood in front of them with an erection and full of expectations. Castle had to admit that Colin was anything but unattractively.

Kate turned red at the thought of what she was going to ask of both men any moment now. "I want you both… in me… at the same time," she began hesitantly, "I want to feel both your cocks inside me."

Colin had kind of already anticipated that and was ready for everything. Castle, on the contrary, looked at her surprised at first, but gathered his bearings again quickly.

"Okay," he directed his next question at Kate, "Who, where, and how?

Kate hadn't gotten that far in her thoughts, this was her first time even voicing that desire. All she knew was that she wanted to be as close to Castle as possible.

"Get on your back," she instructed Castle after a moment's thought. He immediately followed her request. Kate crawled to him on the bed and straddled his thighs. She grabbed his hard cock and gave it a couple of strokes, before she positioned herself above him and sank slowly down onto his cock.

Castle pulled her down and kissed her gently. He let his tongue trail across her lips until she opened them and he could delve deeper into the cavity of her mouth. Kate moaned into his mouth, as he lifted his hips and thrust into her carefully.

Colin savored the sight of the two lovers in front of him, however, he wanted to participate in the games as well. Therefore he cleared his throat to draw Kate's and Castle's attention back to him.

"Where do you keep the lubricant?" He asked Kate when she looked up to him.

"Top drawer," she replied, pointing to the night stand.

Colin retrieved the gel and moved to the end of the bed. He tapped Castle lightly on the shin, so the other man would make space for him. Castle spread his legs apart and Colin knelt in between them. He put his hand on Kate's ass and stroked her cheeks softly. She tensed with excitement, he could see, and then she stopped moving on Castle all together.

"Relax," Colin smirked and kept stroking her lower backside and butt. Castle began stroking her back as well, but stayed near her shoulders, so he wouldn't hinder Colin.

Kate searched for Castle's eyes, reassuring herself that he would not hold a grudge against her over this. When she found his eyes, he gave her an encouraging and loving nod.

Only when Colin could feel Kate's muscles relax, did he squeeze some of the gel between her ass cheeks. The cold startled Kate. But she didn't have time to think about it, because Colin spread the gel quickly and pushed his finger into her anus.

Oh, that felt nice. Kate moaned into Castle's mouth. Her boyfriend and Colin began to move slowly inside her, too slowly. She needed more. She pushed herself alternatively between Castle and Colin to increase the friction. After a few thrusts, Colin added another finger, spreading her.

"Colin, please," Kate begged him, when the tension became too much. She wanted both of their cocks inside her already.

Colin removed his fingers and Kate felt more cold gel and then the tip of his cock against her anus. She tried to relax and was grateful that Castle had stopped moving. This way she could fully concentrate on taking Colin inside her.

She pressed her torso deeper into Castle, resting her head on his shoulder. At the same time she pushed out her butt a little further, carefully to keep Castle from slipping out.

Kate didn't know whether Castle and Colin were using any signals, but suddenly both started moving inside her simultaneously. Castle thrust deeply into her from below, while Colin rocked slowly into her, entering her a little bit more with ever forward motion.

Kate thought she would burst, it was too much and yet not enough. She wanted to come, but then again not really, because it felt so good, this feeling of being completely filled. She wanted to savor it as long as she could. For now she was still in command of her body, but the men moved faster, harder and wilder inside her.

"Come for us, Kate!" Castle encouraged her, as he shoved his fingers between their bodies and rubbed her clit. "I'll catch you."

And then it was time, Kate couldn't stop it any longer. She cried out, alternating both men's names, while her orgasm wrecked her body. She felt as if she'd been flying. And it wouldn't stop because not only Colin but Castle also kept thrusting into her relentlessly.

Just when Kate began to fear that pain might overtake her elated bliss, she felt Castle stopped moving and released inside her. She tensed her vagina's muscles with her last bits of strength, milking every last drop of semen out of him. Her inner contractions also triggered Colin's climax, who emptied his balls for the second time inside her body.

Completely drained and sated, Kate collapsed on top of Castle, bringing Colin down with her, who fell panting on the mattress next to them. Castle rolled away from underneath Kate, so she ended up sandwiched on the bed between him and Colin.

Kate lay on her belly and turned her head to Colin. "Thank you," she exhaled breathlessly, and brushed his cheek.

Colin kissed her softly on the mouth, "Anytime."

Turning onto her other side, Kate sought out her boyfriend, who immediately pulled her close.

"I love you," they said simultaneously and laughed about it freely. Then Kate snuggled into him and was asleep within seconds.

* * *

When Kate woke up again, it was already light outside. She was still lying in Castle's arms. Her boyfriend was snoring softly. Kate withdrew from him because the damp spot she was somehow resting on bothered her. The memories of last night returned and Kate turned around for Colin. But he was gone. She sat up and realized his clothes were no longer on her bedroom floor either. Colin must have slipped out sometime in the dead of the night. Kate sighed because he was a good friend and she found it sad that he hadn't said good-bye. Especially because she wasn't sure if she'd ever see him again.

Castle stirred next to her and rose from his sleep. "Hey," he greeted her, sleep still dazzling his eyes. "Are you ok?"

"Yeah," she smiled in reply, "just a little sore in some places."

"Oh yeah, I can only imagine." Castle grinned and straightened up. "Where's Colin?"

"Gone apparently." Kate shrugged her shoulders. "What did you talk to him about before you came to my bedroom yesterday?"

"Just making sure that we were all on the same page and Colin understood what this was really about." Castle explained.

"Oh and what has all this been about according to you?" She asked unsure.

"You, of course," he replied seriously. "Just you. I made it clear that this was solely about your gratification, not his nor mine either. But turns out he saw it the same way, so we reached a consensus very quickly."

"Then what were the two of you chatting about for so long?" She asked now curiously.

"Wouldn't you like to know?" He retorted laughing and Kate rolled her eyes. "Can't two men enjoy exchanging notes every once in a while? I learned a lot about you… and I kinda like Colin."

* * *

When Kate and Castle came into the kitchen for breakfast after a mutual shower, they found a note on the counter, saying:

_Thank you!  
I had a lot of fun with you both.  
Next time, I want to try something out.  
Castle, get ready._

_Until then,_  
_Colin_

Castle stared at Kate in shock and a little frightened, but his girlfriend just laughed and patted his hand. "Don't worry, Colin's really good at it. You'll like him even more afterwards."

The End

* * *

A/N: Thanks for reading and the feedback. Constructive criticism is always helpful.  
However, no one was forced to read this story. Those who have complained are welcome to do better.


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